Background: Pregnancy offers a special opportunity for women with substance use disorders (SUDs) to change the trajectory of their addictive behavior. Unfortunately, return to unhealthful behaviors is often rapid after delivery1. The physical link between mother and infant during pregnancy that motivates many women to reduce or eliminate substance use1, 2 can be extended with breastfeeding. Breastfeeding promotes the health of the mother and infant and mother-infant attachment2, 3. We hypothesize that the physical and emotional commitment to breastfeeding will serve to motivate women with SUDs to decrease substance use and improve maternal role functioning and infant health outcomes. This R21 will develop a psycho-educational breastfeeding intervention with the goal of increasing the proportion of women who breastfeed and length of time women breastfeed and then pilot test the program's effectiveness. The long-term goal is to evaluate the impact of breastfeeding on substance use and health outcomes for methadone-exposed mother-infant dyads. Specific aims: Aim 1: Develop a psycho-educational breastfeeding intervention for women on methadone maintenance therapy (MMT) and refine measures of change in breastfeeding knowledge and attitudes. Aim 2: Pilot the intervention to: a) Compare rates of breastfeeding initiation and duration among women in one methadone treatment center before, during and after the availability of the intervention;b) Use the information obtained about differences in breastfeeding rates, maternal substance use, gratification with mothering role and severity of neonatal abstinence syndrome to estimate the sample sizes needed to design a larger randomized control trial of the intervention. Methods: The breastfeeding intervention will be developed through focus groups, ongoing research, literature review and expert opinion and will include group sessions to increase knowledge and skill 6months 12 months 6months building, one-on-one lactation support and peer-support. Specific behavioral skills from dialectical behavioral therapy will be adapted for use in the intervention. For the intervention pilot, will use a three-phase time series study design with non- randomly chosen comparison groups selected by interest in breastfeeding and willingness to participate in an intervention. Baseline assessments will include breastfeeding intention, attitude and knowledge, psychiatric diagnoses and social support. Follow-up assessments completed at one month postpartum will include infant feeding outcomes, self-reported substance use and maternal role functioning. Medical record review data will be used to assess neonatal abstinence syndrome severity and maternal substance use three months postpartum. Future Direction: These data will support a multi-site R01 grant where sites that serve pregnant women on MMT can be randomly assigned to receive (or not receive) the breastfeeding intervention. Outcomes will be compared between breastfed and formula fed methadone-exposed mother-infant dyads. Successful interventions will be adapted for women with other SUDs.Project Narrative Mothers and babies exposed to opiates during pregnancy are at high risk for adverse outcomes. Encouraging and supporting breastfeeding could motivate women on methadone to remain in treatment and off of other drugs and improve health outcomes for both mother and baby. In the proposed study, we will develop and evaluate a breastfeeding program in which women on methadone are taught about breastfeeding and skills to overcome social, personal and systems level barriers to breastfeeding.